Method of operating a gas or dual fuel engine

摘要

A method of operating a gas or dual fuel engine (10) combusting a mixture of gas and air is disclosed. In such engines, pre-ignition of the mixture of gas and air may occur at high loads and high temperatures. To prevent such a pre-ignition, a cylinder pressure of the engine is monitored, and a start of combustion in a cylinder (26) is determined from the monitored cylinder pressure. When a time difference between the start of combustion and an ignition timing of the cylinder (26) is less than a predetermined threshold, an opening duration of an associated gas admission valve (38) is decreased to reduce the amount of gas that is supplied to the cylinder (26) in order to prevent the pre-ignition in the cylinder.